doctype helper default value was missing a "1".
diff --git a/system/helpers/html_helper.php b/system/helpers/html_helper.php
index e552b86..3117035 100644
--- a/system/helpers/html_helper.php
+++ b/system/helpers/html_helper.php
@@ -246,7 +246,7 @@
  */
 if ( ! function_exists('doctype'))
 {
-	function doctype($type = 'xhtml-strict')
+	function doctype($type = 'xhtml1-strict')
 	{
 		global $_doctypes;
 
diff --git a/user_guide/changelog.html b/user_guide/changelog.html
index 9ef36d7..8eec51d 100644
--- a/user_guide/changelog.html
+++ b/user_guide/changelog.html
@@ -88,6 +88,7 @@
 <h3>Bug fixes for 1.7.2</h3>
 <ul>
 	<li>Fixed assorted user guide typos or examples (#6743, #7214).</li>
+	<li>doctype helper default value was missing a "1".</li>
 	<li>Fixed a bug with ORIG_PATH_INFO that was allowing URIs of just a slash through.</li>
 	<li>Fixed a fatal error in the Oracle and ODBC drivers (#6752)</li>
 	<li>Fixed a bug where Database Forge's add_column and modify_column were not looping through when sent multiple fields.</li>